This invention relates to an osteogenic osteoimplant made up of, at least in part, elongate bone-derived elements for use in the repair, replacement and/or augmentation of various portions of animal or human skeletal systems. More particularly, this invention relates to the use of an implant made up of a coherent mass of elongate bone-derived elements optionally in combination with bone powder. The elongate bone-derived elements and/or bone powder may be undemineralized bone, partially or fully demineralized bone, or any combination thereof. The method of the invention herein is especially useful in periodontal applications, e.g., guided bone regeneration; plastic and reconstructive surgery, e.g., where the contour of the bone must be modified; and filling of cranial defects; though other skeletal applications are also envisioned.
The use of pulverized exogenous bone growth material, e.g., derived from demineralized allogenic or xenogenic bone, in the surgical repair or reconstruction of defective or diseased bone is known. See, in this regard, the disclosures of U.S. Pat. Nos. 4,394,370, 4,440,750, 4,472,840, 4,485,097, 4,678,470, and 4,743,259; Bolander et al., "The Use of Demineralized Bone Matrix in the Repair of Segmental Defects", The Journal of Bone and Joint Surgery, Vol. 68-A, No. 8, pp. 1264-1273; Glowacki et al, "Demineralized Bone Implants", Symposium on Horizons in Plastic Surgery, Vol. 12, No. 2; pp. 233-241 (1985); Gepstein et al., "Bridging Large Defects in Bone by Demineralized Bone Matrix in the Form of a Powder", The Journal of Bone and Joint Surgery, Vol. 69-A, No. 7, pp. 984-991 (1987); Mellonig, "Decalcified Freeze-Dried Bone Allograft as an Implant Material In Human Periodontal Defects", The International Journal of Periodontics and Restorative Dentistry, pp. 41-45 (June, 1984); Kaban et al., "Treatment of Jaw Defects with Demineralized Bone Implants", Journal of Oral and Maxillofacial Surgery, pp.623-626 (Jun. 6, 1989); and, Todescan et al., "A Small Animal Model for Investigating Endosseous Dental Implants: Effect of Graft Materials on Healing of Endosseous, Porous-Surfaced Implants Placed in a Fresh Extraction Socket", The International Journal of Oral & Maxillofacial Implants Vol. 2, No. 4, pp. 217-223 (1987).
More recently, processed bone has been developed into new shapes for use in new surgical applications, or as new materials for implants that were historically made of non-biologically derived materials.
U.S. Pat. No. 5,556,430 describes the use of a continuous sheet of demineralized bone or partially demineralized bone, however, the sheet must be sufficiently flexible, therefore sacrificing strength, in order to conform to the skeletal site to which it is applied.
However, the prior art demineralized bone products have proven to be unsatisfactory for applications requiring a thin osteogenic material capable of displaying a variety of properties. Commonly assigned U.S. application Ser. No. 09/610,026 filed on even date herewith and incorporated herein by reference discloses a new osteogenic implant.
In one embodiment, the material is thin and conforming, i.e., able to be shaped closely to the exterior of bony surfaces, thereby minimizing stress on the overlying soft tissues. In a different embodiment, the material is form holding, i.e., able to maintain its three-dimensional architecture even after rehydration and deformation prior to or during implantation. This new thin osteogenic material capable of displaying a variety of properties is useful in surgical applications that previously were difficult to successfully treat, e.g., periodontal defects.